This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Glenohumeral arthritis is a disabling condition and may severely affect quality of life and activities of recreation and daily living. Primary glenohumeral osteoarthritis predominantly occurs in older individuals;however, a younger cohort of patients has been recently described with end stage glenohumeral arthritis after shoulder arthroscopy. With shoulder injuries, either acute traumatic event or repetitive stress, the integrity of the cartilage may become compromised due to several factors such as abnormal loading conditions and repeated stresses. Injuries to the glenohumeral articular cartilage can be visualized with MRI, which is the only modality for detailed non-invasive assessment of this joint space. Osteoarthritic changes to articular cartilage such as loss and breakdown of proteoglycan molecules has been quantified with high sensitivity with T1[unreadable] MRI . Therefore, the aim of this study is to develop a T1[unreadable] MRI protocol to accurately quantify biochemical properties of the glenohumeral articular cartilage to monitor the development of cartilage degeneration in vivo.